Sulfurized terpenes



Patented June 22, 1948 2,443,823 SULEURIZED TERPENES Lee Cone Holt, Wilmington, Del., assignor to E. I. du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware N Drawing. Application March 2, 1945,

Serial No. 580,709

This invention relates to non-corrosive sulfurized terpene products, processes for preparing the same and lubricants containing them.

The reaction of sulfur with terpene hydrocarbons to form sulfurized products has been known for many years. Such sulfurized products contain terpene sulfides and considerable amounts of highly reactive or corrosive sulfur generally present either as dissolved sulfur or as polysulfides or both. The terpene sulfides produced are of unknown structure and are usually admixed with by-product hydrocarbons including p-cymene. Such sulfurized products have been concentrated by distillation to yield residues containing large amounts of (sulfur, which is very corrosive, but which does not crystallize from the products. P. 0. Powers, in Patent 1,926,648, has proposed to wash a sulfurized terpene hydrocarbon product free of corrosive and odoriferous impurities with aqueous sodium hydroxide solution. Y

The sulfurized terpene products, obtained by the methods of the prior art, are known to be useful in cutting oils. However, prior to my invention, no one has produced a sulfurized terpene product which has been satisfactory for commercial utilization in automotive lubricants and the like. One of the main reasons for this has been that such products are too corrosive for such use. The best of such products tend to cause pitting of alloy bearings with resultant bearing losses when employed in an"'engine. Such pitting is objectionable. Mostof such prior products, and particularly those prepared from pinene and pine oil, are characterized by bad color, the presence of substantial amounts of insoluble materials and are somewhat unstable at elevated temperatures. j a T It is an object of my invention to provide noncorrosive sulfurized terpene hydrocarbon products useful as additives for automotive and like petroleum lubricating oils and which will impart beneficial properties to such oils. Another object is to provide a novel method for producing noncorrosive sulfurized terpene hydrocarbon products. A further object is to provide new and improved lubricants. Other objects are to provide new compositions of matter and to advance the art. Still other objects will appear hereinafter.

The above and other objects may be accomplished in accordance with my invention which comprises, in part, the steps of sulfurizing at least one terpene of the class of 'dipentene and terpinolene and washing the reaction product at about 85 C. to about 100 C". with an aqueous solution of an alkali metal sulfideof about to about% concentration until a sulfurized terpene product isobtained, which, in 1% concentration in petrol eum oil, will be substantially non-staining ,to

12 Claims. (Cl. 260-139) metallic copper when maintained in contact therewith for 3 hours at C. The resulting products are new and valuable, particularly for use in petroleum oils employed for automotive and like lubrication. Preferred products, however, are obtained by topping the washed product, under vacuum to a pot temperature within the range of from a minimum temperature of about 100 C. to a maximum temperature of about 5 C. above the sulfurizing temperature, until the concentration of sulfur in the product is increased to from about 24% to about 36%. These preferred products are particularly valuable for use in petroleum oils employed for automotive lubrication.

As a means of measuringthereactivity of the sulfur in products of this character and their suitability for use in automotive lubricants and the like, I have employed the copper strip test. In this test, the sulfurized product is dissolved in a petroleum lubricating oil to provide a solution containing an amount of sulfur ordinarily desired for lubricants of this characer. A polished copper strip is exposed to such solution for 3 hours at a given temperature. Thereafter, the color of the copper strip is compared with the color of a standard set of copper strips. The standard strips are numbered from 1 to 10, varying in color from the original copper to: black, as follows:

. Original copper Slight yellow stain Light bronze Medium bronze 1 Dark bronze 1 Weathered copper-purplish Dark weathered copper-red brown-no black Dark weathered copper, with light layer of black soot Dark weatheredcopper with, black areas Black film Since the staining of the copper strip is due to the formation of copper sulfide, this is a very delicate test for sulfur reactivity. The tendency of an additive to corrode copper parts in normal engine operatingconditions is indicated by testing: in the above test at 210 F. All tests given hereinafter are at 210 F. for 3 hours, except where otherwise indicated. To obtain comparable sulfur concentrations, I have generally tested the washed, not topped, oils. at 1% concentrations on the lubricant and the topped additives at /2% concentration on the lubricant. In general, blends of product, giving copper strip values of 5 or less; may be used in lubricants without excessive corrosion under normal operating conditions, although for some types of service, lower values are desirable. This copper strip test is Bronze refers to natural color of polished bronze,

3 a qat ea si -JPFthQd QPI9i9 at 212 gcoppe'r strip) listed iri the Federal StandardStZj'cECatalogf sectiori 4; part Federal specification for lubricants and liquid fuels general specifications (methods for sampling and testing), VV-IP791b. Some measure of'theiavaih ability of the combined sulfur ,fiorr excessive load conditions, in' tures are developed, may be cbtameaby o'p the above test at higher temperatures suc 300 F. or other selected' temperature.

The, terpene hydrocarbons, which are employed to produce the products of my invention are eli pentene, terpinolene and; commercial mixtures thereof. the products may be ,made' Ir p m i t a eii' i a idii i we a e afib ars i vil 39=% a of an isom at a q t 1187 CI. to t amounts of a decrease in yielol In treating mu m in materials, ri i jibf T'qije 1 il be" calculatedbn the basis oithe unsa ration of the" mixture. The reaction ini'iitlire yglill' be maintained at the reaction temple; e for a period of'froin 1 to about"6 hom order to decompose products which are thermally uh's'table at. t e, se ect d rea i n. temperature The rude sulfur zed .prgplu ts. will 1 contain cor: rosiye sulfur and polysulfide materialswhich will hlapliee. opper st at .1003 Qr..be1ow and, hi h a e. hi h QbJG1 Oll lb1- I a e f n that, such objectionable materials can be removed from the crude reactionmixture by washing such reactignmixturewith an agueouscsolution. of an allgal metal sulfi e at temperatures of. from. about C to about Cl Preferably, the alkali metal sulfide will be sodium sulfide. Also, prefer.- ab the aqu us solution will contain the alkali metal sulfide ina concentration. ofirfrom about 2Q% toabQut 30%. The reaction product will be given one, or morewashes" with the,v sodium sul, fide solution, and .until alproductisobtained which, whendissolyed in a petroleum oil in a concentration of 1%, will be substantially non-staining to metallic copper at-100 0;, that is, will-have avalue .pf frsom 1 to 5 .in the copper,strip test hereinbefore described. Generally, itwill be desirable to first wash the crude reaction product one or more times with aqueous caustic soda at 1 about 85 C. to about 100 C. The preliminary washing with caustic soda will not remove the c qrrosive and undesirable sulfur and sulfur comd s lto i th e same extent as will the sodium sulfide b 1; will reduce the amount of sodium sulfi eiequired to remove the undesirable materials {to vthe desired extent.

"=In order to show the advantages of the washmg sodium sulfide over washing with caustic soda, the crude unwashed sulfurized terpenes of Examples lII and VII, described hereinafter, were e lzen. washes with. eme @Qsla and with $0di l sulfide. The crude unwa hed u uriz da o u t f. mammal-1,1 was washed-wi h a 30%. "aque us l fi dmx de sq lltion by agitating thlhe r5115 hoursataw c. This. wa hedprodnet i. then divide int i qrtione- One norliq furthe Washed i h 5( wa l1 se 3 i n h dr xid s lution a 90 em lo -ins L5, l we agitat on n each case- T e l e e mam; wa was d 5 m s n h s me m nn with an. equival nt am nt. Q queous 2. m ulfide sl l-u onf e-re t a e e te i in fine exude. unw sheesl iuriz d eque of IIw'as washed-once with causticisodahand dnto,t oll li iqne Q lelmrt o iwas i a ica tis ashes. Thfih rpor- A s as ,We l. 2 sodium ulfide Wa h s. T eshesjwere .w lllllfited th same ma n a he? ere clecrihe with res ect o h product of Example III. The results of this eatment a e sh wn nfram TAB E; 00

Perfient S nideReaction lOil BfF IJ-NaOH. .a 18.15 hedil n it e L t 1 and 60 Lot-1 after" 2nd NaOH Wash 17;!) rd NaQHWesh- 8-9v 0t 2 after la e la l .v 2 a l. a Wa 1 i iri' ed recincts, as btained: v th wi ium su fid /summe sw ll-have.

s the Wien r: strip tee. li t c wilte are'n vel mat nia en are desirable additives for petroleum lubricating E ore v(16S TABLE 1 3 Pei-Cent Refractive S, lndexilpfll.

rl-N w Wa h-s, 18-97 1..5380 OilSplit into Lots 1 and 2:

Lot 1 after 1s.;a -1 5360 1&4 1.5364: 18.4 155361 18.4 1,5351 13.3 I 1.5370

, 16 t 1.. 5 3;l-1 j 15. 6 1, 5180 3d Na'aS Wash 15. 5 1.5261 Ath N828 Was 15; 1 1 5268 tthNais wa 1512; 232

mass.

'with the proportions of inert materials in the 1 :starting mixture and may be somewhat higher -or lower. Usually, in products of this character,

it is desirable to have higher and more uniform concentrations of sulfur. Also, I have found that the properties of these products can be further improved and that they can be given additional beneficial properties.

The preferred products of my invention will be obtained by subjecting the washed products to distillation under vacuum to remoVe hydrocarbon materials and terpene mono-sulfides. Such distillation will be sometimes referred to herein and in the claims as topping. Preferably, the topping will be carrled out under vacuum of from about mm. to about 60 mm. Care must be taken in this distillation in order to obtain a 'product having, the desired characteristics for use in automotive lubrication and in order to avoid producing a product which will be too cor- :rosive for such use.

Temperatures of about 100 C. or more will be required to remove the desired amount of hydroe carbon materials. However, if the pot temperature is increased to more than about 5 C. above the highest temperature at which the sulfuriza- 'tion was carried out, there is a tendency toward an undesirable amount of chemical condensation :and decomposition to produce products which will contain an objectionable amount of corro- :sive sulfur so that the product will be too corro- :sive for use in automotive lubrication. If the ,pot temperature is maintained at about 125 C. 01 below during the topping operation, there will be substantially no change in the properties of (the product, except those to be expected by con- :centration of the effective sulfurized material. @n the other hand, the topping operation can be carried out at higher pot temperatures to obtain a desired degree of chemical condensation and decomposition of the product with a resultant increase in sulfur activity. This chemical condensation is shown by the formation of terpene mono-sulfide which distills out of the reaction 7 The maximum increase in sulfur reactivity, without obtaining undesirabl corrosive materials, will be obtained by topping to a pot temperature within about 5 C. of the reaction temperature employed for sulfurization. Thus, a product, which is formed by sulfurization at 145 C., will show a considerable increase in sulfur reactivity if topped for about 1 hour at temperatures of from about 140 C. to about 150 C., but will show an excessive increase in reactivity if topped to temperatures substantially above 150 C. On the other hand, a product, reacted at 165 C., may be topped to about 145 C. with little increase in sulfur activity, whereas, if it is topped to temperatures of from about 160 C. to about 170 C. for one hour, there will be a desirable moderate increase in sulfur activity and topping to temperatures substantially about 170 C. will give an excessive and undesirable increase in sulfur activity.

Not only is the increase in sulfur reactivity a function of the temperature in the distillation fore, it is essential that the topping'opration be extended only sufficiently long to increase the concentration of the sulfur in the product to about 36%. A substantial extension of the topping operation beyond thi point, particularly in the higher temperature ranges, tends to result in a product containing an excessive andundesirable amount of corrosive sulfur. Usually, the topping operation, in accordance with my invention, will be carried out until a product is obtained which contains from about 24% to about 36% of sulfur. The copper strip test can also be used to indicate when the product has been excessively cracked during topping. A product, which has been topped to such an extent that it forms a black film on the copper strip, by the copper strip test, is undesirable and has been excessively topped. The topping operation may be aided by passing steam or an inert gas through the product during the distillation,

In order to more clearly illustrate themethods of producing my improved sulfurized terpene products and the products obtained thereby, the following examples are given: 7

EXAMPLE I 84 pounds of sulfur were charged to an iron vessel and heated to 150 C. The agitation was started'and 241 pounds of terpene hydrocarbons (by-product of boiling range 178-195 C, from the camphor process) were slowly added over a period of 3 hours, the temperature being adjusted to" 165 C. during the addition of the first ten percent of the terpene and maintained at 165:3 C. throughout the addition of the balance. After all the terpene had been added, the reaction mass was maintained at 165 C. over a period of six hours. It was then cooled to 90 C. and was agitated for 1 hour with 35 pounds of 30% aqueous sodium sulfide solution, the temperature throughout the period of agitation being maintained at approximately 90 C. The agitation was then shut oif, a few minutes allowed for separation, and the lower aqueous sulfide layer was run off. The sulfurized terpene was given two additional washes with 35 pounds of 30% aqueous sodium sulfide under the operating conditions outlined above. It was then washed free of sodium sulfide solution with hot brine and finally with hot water, The washed product contained 16.65% sulfur and at 1.0% concentration in oil gave a copper strip test of 1.

The washed product was charged to a still and topped under 60 mm. vacuum to a pot temperapot in relation to the reaction temperature, but

i is also a function of the time of heating. "I'here ture of 170 C. The temperature of 170 C. in the pot at 60 mm. was maintained for a period of 1 hour to insure complete stripping of inert material. It was then filtered hot to containers. The finished product, pounds, contained 33% sulfur, and was a clear reddish-yellow oil having a viscosity of 95 Saybolt second at 210 F. When tested in the copper strip test at 0.5% concentration, a value of 5 was obtained.

EXAMPLE II 10 /2 pounds of sulfur were charged to a pot and heated to C. At this temp rature, 26 pounds of the terpene hydrocarbons used in Example I above were slowly added over a period of 1 hour at 145 C2 C This temperature was then maintained for an additional 1 /2 hours. The charge was cooled to 90 C. and was then agitated with 7% pounds of 30% sodium hydroxide for 1 /2 hours at a temperature of 90 C, The agitation was then shut off and the caustic layer separated. The product was then agitated with ajddedl over atppi oi in1 ate 1 1 1z 110mg, poring the mmr 'was s ills edtq fi 3 ma the last 90% of the terpene glft agiqition was complete, the te glpeggturewas held t 165 C.

for 3 hours. It was 'then cooled to 90 C., and'fi :pounds M13095 aqueou tsodium hydroxide were :a.c1g1ed.a= The-reaction. wasvwas agitatecLvigomously i with theea-ustic fort-1 /2 hoursat 98 C..,.thenthe H agitatioriwas-shut OK (and the'eaustic 1ayer seperated.#Eheprsoduct was then vagitated with"'9 pounds ofl 24%sodium sulfide-solution for 1 /2' 1 l' 'oiirs atv90 (3.; following which the-sulfide soluti'onwas geparated. '24 'pounds oflwashed product were obtainedl- 'lhis; product c'ontined tratio i in the-copper strip test, gavea va lue ofll.

The washed. product was cliar gedto a still and.

l toppedto 170 Get-50 min.- 1l-poundslof residue were obtainegi eontaining-33-.96%- sulfun-I. The --;-r-esiduev,(asalight colored reddish-yellow oil havi ing a, iscosity of 100.3 Saybolt seconds et-210 F. At-0.5%Qcpncentratiofidn the copper strip test, a

- value-of 4 was-obtained, l y some water ,JEXAMPLE IV 455 i4 0 ,wzwThe-terpenehydrocalrbons, useddn this..exampie 'consistecl .of U an commercial (mixture; which contained.;.a,pproxima,telydipentene; 25%

- terpinolene; 15%ip-oymene, M11120 pl-menthane.

Ha; JI-helattertwoi ingredientsare inert and may be distilled out of the-finallproduct.

,1 .153 pounds. of sulfur were-chargeditota. reactor qand heated toe-temperature of 150.G. .-Th en 148 pounds of the terpene mixture were added gmdu- I I -a1ly at '1 't0150 -Cr over 3-houra1ftetwhidh the A 4 temperature Was-maintained et 150 C; for an {additionaLS hours-.-- The charge wasthen cooled I C t)90 C.--a -ndagitatedwith 46pounds-of 25% sodium- 'sulfijie solution ford-hour a-t 90 CL 'The 6 sulfide solutio n' wag allowed to settle and was separated. The Washing esthen twice repeated with equal amounts of --sodium"-sulfidesolution. Finally sodiumisulfidfi silll ltion was washed from 2 the pi voductu-hymeansof,hotbrinegmcl lgot, water.

4 i izhjeyg a hed d; tested a.t'1.9 ooneentmtion, gave "e pat and;

opp trip est'pf ;1., ,Tkie waslied piodt ct Was 1i: er -ed to-e sti l a do o n o '1. 0? tem -1 IVI'ZQZ'H u' axml. t k 4 w l H wash for 1 hourat 90C. After separating the iiped farmer.

second sodium sulfide wash, the charge was distilled under 20 mm. vacuum to a pot temperature of 100 C. '73 grams of distillate and 698 grams of residue were obtained. After filtration, the

residue contained 23.98% sulfur and gave a satisfactory copper strip test.

It will be understood that the above examples blended with chlorinated hydrocarbons make efare given for illustrative purposes solely and many variations can be made therein without departing from the spirit or scope of my invention. For example, other commercial mixtures of terpene hydrocarbons of the character hereinbefore defined may be treated by the same methods. Also,

equivalent materials have been prepared from pure dipentene, pure terpinolene and the pure isomeric terpene hydrocarbon of boiling point 187 C. to 188 C. separated from the mixture employed in Example I.

All of the products of the examples, including the products washed with sodium sulfide but not topped, are viscous oils and are yellow or reddishyellow in color. They are further characterized by the fact that their solutions in petroleum lubricating oils will not attack copper to any appreciable extent or blacken it when subjected to the copper strip test hereinbefore described at 100 C., but will react with and blacken copper in the temperature range of from about 120 C. to about 200 C. The sulfur in the products apparently begins to become active to deposit a black cop per sulfide film on a copper strip at temperatures of about 120 C. to about 130 C. In some preparations, this temperature of reactivity may be as low as 110 C., but will always be above 100 C. Most of the sulfur becomes active to blacken copper at temperatures of from about 150 C. to about 170 0., whereas, by 200 C. nearly all of the available sulfur will have reacted. This reactivity of the sulfur at these temperatures appears to be essential for the products to exert their beneficial effect on lubricating oils and particularly to produce extreme pressure properties.

The sulfurized terpene hydrocarbon products of my invention are very efiective antioxidants for highly refined mineral oils and for pure oxidizable hydrocarbons in the temperature range of fective and economical bases for hypoid gear lubricants.

The effectiveness of my compounds as oxidation inhibitors at high temperatures may be illustrated by their eifect on inhibiting the oxidation of cetane as shown in Table 3. The products emplcgyed in these tests were the final topped produc s.

TABLE 3 Oxidation of cetane [Gonditionsz 1,000 cc. of air per minute through a 33.3 gram sample of cetane in a glass system] i Induction Additive 83. 6g? Temp. Period,

Minutes 150 49 150 190 150 over 420 175 2 Example 1 0. 15 175 340 The value of these non-corrosive sulfurized terpene hydrocarbons as additives for use in extreme-pressure lubricants has been established by the tests outlined in U. S. Army Specification No. 2-105, dated September 10, 1943, and entitledLubricant; Gear, Universal (Hypoid and Other Types).

Table 4 lists the data obtained with the topped products of Example I and Example VIII and also lists comparable results with dibenzyl disulfide which has been accepted as satisfactory by the army for this type service. In all cases the E. P. L. bases tested contain three parts of chlorinated product to one part of the sulfur additive. Two chlorinated products are used: (1 a chlorinated naphthalene and (2) a chlorinated paraffin containing 40% chlorine. The base oil used is a commercial hypoid gear petroleum base oil.

TABLE 4 90% Base Oil-H547 Chlorinated 90% Base 0il+7%% Chlorinated naphthalene+2%% of Sulfur Paraflin+2%% of Sulfur Com- T ts Base 011 No Compound pound es Additive A Ex. 1 Ex. 8 BEDS Ex. 1 Ex. 8 DBDS Copper strip at 212 F N Neg Neg Copper strip at 300 F N Pos SAE Load Carrying Capacity:

1000 R. P. M. before heatmg 340 310 500 R. P. M. after heating 435 450 Emulsion fest 2 37 35 Channel test Pass P Passes Viscosity S. U. S. 210 F 83.8 79,7

Ex. 1-Su1i'. terpene hydrocarbon of Ex. 1 33% S. Ex. 8-Sulf. terpene hydrocarbon of Ex. 8 24% S. Chlorinated parafiin--(40% chlorine).

1 Tests from U. 8. Army Spec. No. 2-105.

from about 120" c. to about 200 0., but are ineffective for this purpose at temperatures of 100 C. and below. They are also effective corrosion inhibitors for copper, silver and their alloys when The sulfurized terpene products of my invention are also useful for improving thencetane value of Diesel fuels. For such purpose, they will be added to the Diesel fuel oil in the proporiollowingtest.datasappearing' in Tableriwherein the toppediproductzof Example-I was employed:

TABLE 5 Concper Increaseln Additive cent Cetane No. Cetane'Nor 47.5 50.6 3.1 .50 51.9 4.4 1.00 V 52.5 5.0 Example l.- 2. 55. 2 7. 7

P. C). Powers; :in Patent 1;92 6,648,:discloses the I preparation of non-corrosive sulfurized terpenes suitable for use as cuttingnfluids. In order to show more clearly the advantageous properties of the products of my invention over the products of Powers, sulfurized terpenes were made in accordance with the disclosure of Powers and subjected to the copper strip test. First, sulfurized pine oil and sulfurized a-pinene were prepared as follows:

Sulfurized pine oil 400 grams of sulfur'and 800. grams of pine'oil' were placed in a flask and heated to a temperature-oi 178-l80 C. At this point a vigorous re-"- actionoccurred, -and--the temperature rose to 1903C. :The-heat:was shutofi until the reaction moderated -which took about 5 minutes; and

then the theatwwas again-r applied and the temperaturea-raisedto 210.;.C. over a period of 30 minutesgyaThe" total: time was about 1 /2 hours."

Sulfurized a-pinene 400 grams of sulfur and-800 gramsof a-pinene were charged-to aflask and heated under reflux to 158-160" C. Reflux was maintained at this It took about one -hour for thessulfur to dissolve-and the sectemperature .for about two hours.--

ond houncompletedthe-reaction.

Eacn -of these-productswas then washed by agitating with a 20%- aqueous sodium hydroxide solution-at 90 -C. to 95 C., employing'suficient solution-to provide: 6 parts of sodium'hydroxide.

for each .l-OO partsof thesulfurizedterpene...

Samples of the sulfurized terpene were withdrawn, after washing for 15 minutes, 30 minutes, minutes and 120 minutes, the sodium hydroxidewashedtherefrom 'withwater and the samples thenvsubjected to the-hopper strip test herein-.5." before described. The-results of such tests are shown in Table 6:

TABLE'G" H 3 hour, 210, F. copper strip iest samples at 1.0%

and 5.0% cone. in SAE 10 oil Sulfurized sulfunzedlme O11 Timeofl Example of Powers a 3 3 Wash Agitation,v qmva e Min.

1.0% 00110. 5.0% Oonc. 1.0% 5.0%

15 10 10 10 10 30 10 1O 1O 10 60 10 10 10 10 120 10 10 1O 10 From thesetests, it, will be apparent that,

whilethe products'ofPowers are suitable for outting :oillubricants, they-did not have the required propertiesin the copperstrip test .to make them-suitablefor. use in automotive lubricants.

in thesamemanner as the compounds of my invention.

In preparing lubricants from my sulfurized hydrocarbonimateriais in therhighe'r' temperature" ranges-and which:areparticularlwsuitablei or iuse: in automotive. lll'bIlCfllltSijIt i'svalsoapparent that,'x= by 1i1fiinVntiDh;I have provide'dsuliurizedlief-1:" pene.productsmhich'are useful in extreme=pres= w sure lubricants whereinone'corrosive: properties are requiredxahdshave alsoiprovided'compounds which r are "effective tor iinhibitingrbearing corrosion. I

believe that I am the first to provide s'uliurized terp'eneprotducts fOf 'suc-hicharacter andwwhich are.

like-rt.

I claimioir 1. A suliuriz'ed terpeneproduct' obtained by the sulfurizationof at leastwonemember of the Jgroupi consisting .of dipentenei and terpinolene: :followed by 'washingiithecsulfurizationproduct at about 1C. to abouttlOOiiC; withen aqueous solution I suitable'iior useiin automotive lubricantsrand: the: r

of anvalkalixinetal sulfidez 'of a. concentration of about=z20% to 30%? untilw'a2 productx-is obtained WhiChll in kdilute petroleum oil :'solution-"wi1l" not-:2-

whiclsr will form "black filmsl'on metallio'coppenat '2 tempei'aturesabetween 120210; andi200'f C. i

2. A siilfurized terpen'elproduct'obtained. by the r sulfuriz'atioh ofat lea'stonefmember of thegroup consisting of dip'ehtene'and 'terpinolerre;washingr form blaclo'filnis on metallic copperr'at lOO CL' but" 1 the sulfurizatioriproduct at about 8530. to about f 20? with an aqueous solution of an 'alkali metal.

sulfideilof: afconc'entraitiorrroi about%' to about centta'tion in petroleum (oil omits substantially 3: non-staining to met'adlicieopperiat :lfifisrC xthen toppin' he washedt-productwunde'rfvacuumto a;

potit em perature .n'i from aboutPiOuiiC'. to about =5? (31' apove the sulfiunzing .temperatur'eito obtain? a product whicht cont'ainsTfirom :1about 24%:'to about 36% of chemically combined sulfur and is substantially free of hydrocarbons and which product in dilute petroleum oil 7 solution will not form black filnis on metallic copper at 100 C. but which-willforr'n black films on metallic copper at temperatures between 120 C. ahd=200 C.

3. A sulfurized terpene product obtained by the sulfurizationhf a mixture of terpenes the major proportion...ozf which consists of dipentene and terpinolene; followed by washing-thesuliurization\ product at about 85 C'. to aboutt-lOO YC. With'an aqu'eoussolutionof ail-alkali rnietal'csulfide of a concentration 01? about20%to about'30%""until a. product is-obtained which in dilute petroleumtoil u solution'will not form black filmson metalliccop' per at 100 C. Hill) which 'Will' form blackfilms'on M metallic copper:at temperatures;betweenfilflo "C. and 200 C.

4. A sulfurized terpeneproductobtaiinedby the sulfurization of a mixture of terpenes the major proportionpf whicheonsistsof dipentene and terpinblene," washing the sulfurization' product at about;85 'CL'to about100" Cf'withan aque'ous'solu tion of an alkali. metal sulfide of a concentration of about 20% to about"30% until'a product is 'obtained;whichtin'l% concentrationin petroleum oil will,he substalritially honestaining'to metallic copper at 100" 'the'n'topping me washed. product under vacuum to'a' pot temperature of fromab out 100 C. to about C. above the sulfurizing temperature to obtain a product which contains from about 24% to about 36% of chemically combined sulfur and is substantially free of hydrocarbons and which product in dilute petroleum oil solution will not form black films on metallic copper at 100 C. but which will form black films on metallic copper at temperatures between 120 C. and 200 C.

5. The process which comprises heating at least one terpene of the group consisting of dipentene and terpinolene, with sulfur at from about 135 C. to about 180 C. until a substantial proportion of the terpene is sulfurized and washing the reaction mixture at about 85 C. to about 100 C. with an aqueous solution of an alkali metal sulfide of a concentration of about 20% to about 30% until a product is obtained which in 1% concentration in petroleum oil will be substantially non-staining to metallic copper at 100 C.

6. The process which comprises heating at least one terpene of the group consisting of dipentene and terpinolene, with sulfur at from about 135 C. to about 180 C. until a substantial proportion of the terpene is sulfurized and washing the reaction mixture at about 85 C. to about 100 C. with an aqueous solution of sodium sulfide of a concentration of about 20% to about 30% until a product is obtained which in 1% concentration in petroleum oil will be substantially non-staining to metallic copper at 100 C,

7. The process which comprises heating at least one terpene of the group consisting of dipentene and terpinolene, with sulfur at from about 135 C. to about 180 C. until a substantial proportion of the terpene is sulfurized, washing the reaction leum oil will be substantially non-staining to metallic copper at 100 C., then topping the washed product under vacuum to a pot temperature of from about 100 C. to about 5 C. above the sulfurizing temperature until the concentration of sulfur in the product is increased to from about 24% to about 36%.

8. The process which comprises heating a mixture of terpenes the major proportion of which consists of dipentene and terpinolene with sulfur at from about 135 C. to about 180 C. until a substantial proportion of the terpene is sulfurized and washing the reaction mixture at about 85 C. to about 100 C. with an aqueous solution of an alkali metal sulfide of a concentration of about 20% to about 30% until a product is obtained which in 1% concentration in petroleum oil will be substantially non-staining to metallic copper at 100 C.

9. The process which comprises heating a mixture of terpenes the major proportion of which consists of dipentene and terpinolene, with sulfur at from about 135 C. to about 180 C. until a substantial proportion of the terpene is sulfurized and washing the reaction mixture at about 85 C. to about 100 C. with an aqueous solution of sodium sulfide of a concentration of about 20% to about 30% until a product is obtained which in 1% concentration in petroleum oil will be substantially non-staining to metallic copper at 100 C.

10. The process which comprises heating a mixture of terpenes the major proportion of which consists of dipentene and terpinolene, with sulfur at from about 135 C. to about 180 C, until 14 a substantial proportion of the terpene is sulfurized, washing the reaction mixture at about C. to about C. with an aqueous solution of sodium sulfide of a concentration of about 20% to about 30% until a product is obtained which in 1% concentration in petroleum oil will be substantially non-staining to metallic copper at 100 C., then topping the washed product under product under vacuum to a pot temperature of from about 100 C. to about 5 C. above the sulfurizing temperature until the concentration of sulfur in the product is increased to from about 24% to about 36%.

11. The process which comprises heating a mixture of terpenes the major proportion of which consists of dipentene and terpinolene, with from about 1.5 to about 2.1 atoms of sulfur for each mole of the unsaturated terpenes at temperatures of from about 160 C. to about 170 C. until a substantial proportion of the terpenes is sulfurized, washing the reaction mixture at about 85 C. to about 100 C. with an aqueous solution of sodium sulfide containing about 20% to about 30% sodium sulfide until a product is obtained which in 1% concentration in petroleum oil will be substantially non-staining to metallic copper at 100 C., then distilling off hydrocarbons from the washed product under vacuum of about 50 mm. to about 60 mm. to a pot temperature of about 170 C. until the concentration of sulfur in the product is increased to from about 33% to about 34%.

12. The process which comprises heating a mixture of terpenes the major proportion of which consists of dipentene and terpinolene, with from about 1.5 to about 2.1 atoms of sulfur for each mole of the unsaturated terpenes at temperatures of from about 140 C. to about 150 C. until a substantial proportion of the terpenes is sulfurized, washing the reaction mixture at about 85 C. to about 100 C. with an aqueous solution of sodium sulfide containing about 20% to about 30% sodium sulfide until a product is obtained which in 1% concentration in petroleum oil will be substantially non-staining to metallic copper at 100 C., then distilling off hydrocarbons from the washed product under vacuum of about 10 mm. to 30 mm. to a pot temperature of about C. toabout C. until the concentration of sulfur in the product is increased to from about 30% to about 34%.

LEE CONE HOLT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,926,648 Powers Sept. 12, 1933 1,926,687 Palmer Sept. 12, 1933 1,929,955 Nelson Oct. 10, 1933 1,963,084 Gardner June 19, 1934 2,012,446 Edwards Aug. 27, 1935 2,034,665 Ott Mar. 17, 1936 2,043,961 Kaufman June 9, 1936 2,045,788 Maverick June 30, 1936 2,076,875 Borglin Apr. 13, 1937 2,137,410 Moran NOV. 22, 1938 2,156,919 Merriam May 2, 1939 2,246,282 Zimmer June 17, 1941 2,329,486 Rummelsburg Sept. 14, 1943 2,332,165 Ott Oct. 19, 1943 Certificate of Correction Patent No. 2,443,823. June 22, 1948.

LEE CONE HOLT It is hereby certified that errors appear in the printed specification of the above numbered etent requiring correction as follows: Column 7, line 12, for the word has read line 27, for was first occurrence, reed mass; line 49, for 20 p-menthene read 20% p-menthane; column 12, line 29, claim 1, for 20% to 30% read 20% to about 30%; and that the said Letters Patent should be read with these ao'irections therein that the same may conform to the record of the case in the Patent Signed and sealed this 24th day of August, A. D. 1948.

THQMAS F. MURPHY,

Assistant G'ommissioner of Patents. 

